Polyphosphates of divalent aryl hydrocarbons



l i'tliil' his EQEQQQQQQ u r A Patented Au 22, 1950 rotrrno muscles ormutant can. mnocsnmns Gerald it. Eirreit, Winchester, Mass asslgnor toMonsanto Chemical Company, St Loub, M55, a corporation of Delaware noDrawinz.

Application December 30, 1947, Serial No. 794,799

This invention relates to the preparation of polyphosphate compounds,and particularly to the preparation of polyphosphate compounds havingunusual plasticizing properties.

It is a primary object of the invention to paepare polyphosphatecompounds of the type described which are thoroughly compatible vnthnitrocellulose and other cellulose derivatives, such as ethyl cellulose,cellulose aceto-butyraie, and the like and which are characterized byiow solubility in mineral oils and other petroleum hydrocarbons.

A further object of the invention to prepare plasticizing compounds oithe type described which are adapted to impart flame resistantproperties to the cellulose derivateves to which they are added andwhich are characterized by being relatively non-volatile.

Still further objects and advantages of the invention will appear fromthe following description and appended claims.

The objects of the invention are accomplished in general by reacting amixture of monohydric and dihydric phenols with suflicient phosphoruspentachlcride or phosphorus oxyehloride or mixtures thereof to form aneutral product. The molar ratio of monohydric phenol to dihydric phenolused should be 4 to 1 in order to obtain compounds of suitableplasticizing properties. When the molar ratio of mono and dihydricphenols employed is 4 to 1, two mole of the phosphorus halide compoundshould be used in order to obtain neutral compound; of t a desiredcharacteristics.

Polyplhs'phate compounds are described in the alzie for use asplasticiting agents in nitrocellulose or other cellulose derivativecompositions.

2 By proceeding in accordance with the present invention compounds ofthe following general formula are prepared:

wherein X represents a, dihydric phenol residue, and R represents anaryl. radical.

The dihydric phenols which may be used to prepare compounds of the abovenature include rescrcinol, hydroqulnone and polynuclear phenols such asdiphenylol methane, diphenylol dimethyl methane, dihydroxy diphenyl,p,p' dihydroxy diphenyl sulfone and dihydroxyl naphthalene. Themonohydric phenols which may be used include phenol, cresol, xylenol,tertiary butyl phenol and the like.

If desired, the dihydrlc phenol may be formed in the reaction mixture byud-"Jng suitable molecular proportions of mono'nydric phenol and analdehyde, such as formaldehyde, acetaldehyde or the like. Thus, when theratio of mono and dihydric phenol desired is 4 to 1, six mols of phenolwould be reacted with one moi of aldehyde and suflicient phosphorushalide to produce a neutral compound, 1. e. two mols. Two mole of thephenol would then react in situ with the aldehyde to form a dihyc ricph; 101, which in turn reacts with the four remaining mols of phenol andthe phosphorus comp mud to pro duce the desired end product. In suchinstances, it is essential that a relatively large proportion of thephosphorus halide employed be phosphorus pentachloride, which isconverted to phosphorus oxychloride by reaction with the water formed asa result of the phenol-aldehyde condensation.

A further understanding of the invention will be obtained from thefollowing examples of methods of preparing the polyphosphate compoundsof the type described.

Example I Two hundred and fifty grams of phosphorus oxychloride weremixed with 20 grams of phos- By proceeding in the above manner theresorcinol reacts first with the phosphorus onohlcride as iollows:

o-roch OK Queen. +anci H -POC1$ r-rock summon E )l-POCI:

( i-t 0mm):

The phosphorus pentachloride and AlCh were employed to promote thereaction by catalysis and reaction with any traces of moisture.

Example II Two hundred and four grams of phosphorus oxychloride weremixed with 20 grams of phosphorus pentachioride and 1.5 grams of A161:and heated under reflux. Seventy-six grams of diphenylol dimethvlmethane were then added to the mixture in small increments over a periodof two hours, while heating the mixture under reflux. The heating underreflux was continued until the evolution of H01 ceased, after which theexcess phosphorus oxychloride was distilled oil. One hundred andtwenty-five grams of phenol were then added to the residue in the courseof an hour, while maintaining the residue at a temperature of 100 to 125C. The mixture was then heated for about four hours at 150' 0., afterwhich the product was purified in the marmer described in Example I. Theproduct thus obtained was a light brown viscous liquid of negativechlorine and monophosphate content, which contained 1 to 2% volatilematerial. The yield was 92% based on the theoretical 100% conversion orthe diphenol to the desired diphosphate.

Emmple III Twenty-two and eight tenths grams of diphenylol dimethylmethane were mixed in a suitable reaction vessel with 20 grams ofphenol, 29 grams of phosphorus oxychloride and 2.4 ns oi phosphoruspent-achloride, after which he mixture was heated in an oil bath for 1%hours, during which time the temperature of the bath was graduallyraised to 150 C. After cooling the material and replacing the HCl in thesystem with dry air, so grams more of phenol were added, and the mixturewas heated at 21 4 C. for about 3 hours or until the evolution of HClhad practically ceased. The resulting material was dissolved in benzol,washed with a concentrated KzCO: solution and dried over K after whichthe benzyl was removed by distillation. The product thus obtainedconsisted of c? grams of a dark straw colored oil. or essentially 100%of theory. The oil was insoluble in keroacne and compatible withmtrocelluioso in all proportions.

Example rv Three and three tenths grams oi powdered paraiorm weresuspended in 40 grams of melted phenol contained in a suitable reactionvessel. atter which 18.5 grams oi phosphorous oxychloride were added andthe resulting mixture was warmed cautiously. Upon completion or thereaction, the mixture was cooled and 23 grams of phosphorus entachloridewere added and allowed to react. Finally 20 grams of additional phenolwere added and the mixture was heated in an oil bath until the evolutionof HCl practically ceased. The maximum tem erature reached up to thispoint in the reaction was 0., and then the reaction was completed byheating the mixture with the bath at 200 to 230' C. The result ngmixture was further treated as described in Example 111, and as a result60 grams (representina a 95% yield) of a very viscous, palestraw-colcred o l was obtained. which was compatible with nitrocellulosein all proportions.

If desired, the products prepared in accordance with the above examplesmay be decolorized in al o ol sol tion with activated carbon. Themethods used in Examples I and II, in which the diphenol is firstreacted with an excess of phosphorus oxychloride before adding themonobydric phenol, are preferred, since these methods result in productswhich are completely or substantially free of the monophosphete.

Although in general the plasticizers prepared as described herein havebeen described as usetul primarily in cellulose derivative campedtions,it is to be understood that they may also be used effectively asplasticizers in other materials, as for example in synthetic rubbercompositions, polyvinyl chloride and copolymers of vinyl chloride withother vinyl monomers.

This application is a continuation-in-part at my copending applicationSerial No. 497,057 tiled August 2, 1943, now abandoned.

What is claimed is:

1. A plasticizing agent consisting of a. polyphosphate compound of thefollowing general formula:

- nucleus and R represents a mononuclear aryl hydrocarbon radical.

2. A plasticizing agent consisting oi a polyphosphate compound havingthe following formula:

0 CcHsO- 3. A plastioizing agent consisting of a polyphosphate compoundhaving the following formula:

o cm o c.n.o l a l c o l oc.m cano on, octm 4. A plasticizing agentconsisting of a poly- 5. A plasticizing agent consisting of apolyphosphate compound having the following formula:

6. The method of preparing a plasticizing agent having the generalformula:

0 O RO-Q-WX-O-l-OB B0 OR 6 which eomprisa heating 1 molar proportion ofa dihydric phenol of the formula HO-X-OH, where x is a divalent arylhydrocarbon radical in which each free valence stems from an arylnucleus, with 2 molar proportions of P001: until 2 molar proportions ofHCl are evolved, then adding 4 molar proportions of a monohydric phenolof the formula ROE, where R represents a. mononuclear nryl hydrocarbonradical, and heating until a product of the above general formula isformed.

GERALD R. BARREI'1.-

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS I OTHER REFEREIICES Knmzer. Ber. deutseh. Chem.Ges.," vol. 27

1. A PLASTICIZING AGENT CONSISTING OF A POLYPHOSPHATE COMPOUND OF THEFOLLOWING GENERAL FORMULA: